Probably. As a general rule of thumb, things will work going forward, but not necessarily going backwards. So, if an app was made for XP, there's a reasonably good chance it will work on Vista, 7, 8, etc, but not necessarily 9x-Me.
The download for the CNET Savings Bond Wizard mention the requirement for several Windows operating systems, but does not mention the Windows 7 operating system. Is it safe to download it to Windows 7?